In the prior art vehicles, indication lights are installed at the front and rear sides of the vehicles. They only alert the cars or people coming from the front and rear sides of the vehicles. However no light is installed at the two lateral sides of the vehicles. In many cases, the accidents are induced from the collisions at the lateral sides, for example when the vehicles run across a crossroad. Thereby there is an eager demand for a novel design which can improve the prior art defects.